Nationals Park, home of the Washington Nationals /Other/Ceco/Images/large%20project%20photos/Nationals_Park_front.jpg Architect: HOK Sport/Devrouax-Purnell Architects Ceco Distributor: Custom Engineered Openings National's Park is the first LEED certified green stadium in the country. LEED certification was awarded because of the park’s water conserving plumbing fixtures and it’s the use of recycled materials in 20 percent of the park’s construction. The over 700 steel-stiffened Medallion doors and 800 masonry S - series frames were used for the park’s construction. They were distributed by Custom Engineered Openings in Baltimore, Maryland, and produced by CECO Door. The doors and frames are made from recycled steel, which contributed to the LEED requirement usage of total building materials being made of 20 percent recycled materials.